Julian Astle writes about politics and public policy. He previously worked as director of CentreForum, the liberal think tank, and as Political Advisor to Paddy Ashdown when leader of the Liberal Democrats. He is @JulianAstle on Twitter.

The danger of the Barnsley by-election for Labour

Ed Miliband is leading Labour back to the 'soft Left' (Photo: Rex Features)

By-election results are like good anecdotes – entertaining, often hugely enjoyable (especially for lovers and haters of particular tribes) but not necessarily very informative.

As a former Lib Dem staffer, I remember all too well what it is like to wake up on the morning after a by-election victory that, in the words of the victorious candidate, "sends a powerful message to (insert name of governing party) that the people of (insert name of constituency) reject this discredited government's approach to (insert main public policy challenge of the day)". I also remember just how tempting it is to believe your own rhetoric in such circumstances, and how dangerous it is to interpret the victory as an endorsement of your leader, your policies and your strategy.

So while it is the Lib Dems who face the most uncomfortable task today as they try to explain away a very bad result, it is the Labour leadership that should be most on its guard. For it is they who face the difficult but critical task of disbelieving the message the people of Barnsley appear to be sending them. It is they who need to look behind their 60 per cent vote share and ask whether it really tells them anything at all about how they, rather than the government, are doing, or indeed, what the people of the United Kingdom, rather than Barnsley, are thinking.

The people of Barnsley were answering two questions when they cast their ballots yesterday. First, and most obviously, whether they like or dislike the coalition government (made up of Conservatives and Liberal Democrats, two parties they didn't support in significant numbers even when in opposition). Second, whether they like or dislike what that government is currently doing (raising their taxes and cutting their benefits and services in the name of deficit reduction). Unsurprisingly, they decided they disliked both and voted accordingly.

But the people of Barnsley are not representative, and, under our First Past The Post electoral system, don't actually matter. It is swing voters in swing seats that decide general elections, not people in places like Barnsley. What is more, although six in ten of them voted for the Labour party, they were not, in any meaningful sense, passing judgment on the Labour party. For both these reasons, the result tells us nothing at all about the merits of Ed Miliband's only strategically important decision to date: to declare New Labour "dead" and to lead his party back to its "soft Left" comfort zone. Whether he can win a general election from there, or whether, as Tony Blair still believes, the party can only win from the centre, is the key question for Labour strategists. But the Barnsley by-election result won't get them any closer to the answer. If anything, it will take them further away.